4,805 research outputs found

    Nanodiamonds with silicon vacancy defects for nontoxic photostable fluorescent labeling of neural precursor cells

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    Nanodiamonds (NDs) containing silicon vacancy (SiV) defects were evaluated as a potential biomarker for the labeling and fluorescent imaging of neural precursor cells (NPCs). SiV-containing NDs were synthesized using chemical vapor deposition and silicon ion implantation. Spectrally, SiV-containing NDs exhibited extremely stable fluorescence and narrow bandwidth emission with an excellent signal to noise ratio exceeding that of NDs containing nitrogen-vacancy centers. NPCs labeled with NDs exhibited normal cell viability and proliferative properties consistent with biocompatibility. We conclude that SiV-containing NDs are a promising biomedical research tool for cellular labeling and optical imaging in stem cell research

    Effect of soy on bone turn-over markers in men with type 2 diabetes and hypogonadism – a randomised controlled study

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    Type 2 diabetes (T2DM) is associated with increased risk of fractures. Soy supplementation has been shown to have a beneficial effect on bone turnover markers (BTM) in postmenopausal women. However, the effect of soy supplementation on BTM in T2DM and particularly in men is unclear. We performed an analysis of a randomized double blind parallel study of 200 men with T2DM treated with soy, either with or without isoflavones. Outcome measures were type I collagen crosslinked beta C-telopeptide (βCTX), and type 1 procollagen-N-propeptide (P1NP). The men, with a total testosterone <12 nmol/L, were treated with 15 g soy protein containing 66 mg of isoflavones (SPI) or 15 g soy protein alone without isoflavones (SP) daily for three months. There was a 15% reduction in βCTX after three months of SPI compared to SP supplementation. There was no significant difference in P1NP with either SPI or SP supplementation. There was a significant linear correlation between the reduction in βCTX in the SPI group with the reduction in HbA1c (r2 = 0.42; p = 0.04) and HOMA-IR (r2 = 0.54; p = 0.02). Our study indicates that there was a significant reduction in bone resorption following 3 months of SPI supplementation that correlated with an improvement of glycemic control in men with T2DM

    Disparate Effects of Atorvastatin Compared With Simvastatin on C-Reactive Protein Concentrations in Patients With Type 2 Diabetes

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    OBJECTIVE - Reduction in LDL and high sensitivity (hs) C-reactive protein (CRP) are independent indicators of successful cardiovascular risk reduction with statins. This study compared the effect of equivalent LDL-lowering doses of simvastatin and atorvastatin on hsCRP in type 2 diabetic patients. RESEARCH DESIGN AND METHODS - A crossover study of 26 patients with type 2 diabetes taking either 40 mg simvastatin or 10 mg atorvastatin was undertaken. After 3 months on one statin, lipids and hsCRP were measured on 10 occasions over a 5-week period. The same procedure was then followed taking the other statin. RESULTS - LDL was comparable on either treatment: atorvastatin 2.2 +/- 0.2 vs. 2.1 +/- 0.3 mmol/l (mean +/- SD; P = 0.19). CRP of individuals taking atorvastatin was significantly lower than when they were taking simvastatin (median 1.08 vs. 1.47 mg/l, P = 0.0002) and was less variable (median SD of logCRP 0.0036 vs. 0.178, P = 0.0001). CONCLUSIONS - Compared with simvastatin, atorvastatin reduced hsCRP and its variability in type 2 diabetic patients. This enhanced anti-inflammatory effect may prove beneficial if lower CRP is associated with improved cardiovascular risk

    Does R&D spur productivity growth in Australia’s broadacre agriculture? A semi-parametric smooth coefficient approach

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    © 2018 Informa UK Limited, trading as Taylor & Francis Group This article analyses the role of research and development (R & D) in Australia’s broadacre farming by using the semi-parametric smooth coefficient model. While the conventional production function approach only captures the direct effects of R & D, this methodology captures both the direct impact of a change in R & D on output and the indirect impact through changes in efficiency of use of factor inputs in the production process. Moreover, technical inefficiency is introduced in the model allowing it as a function of R & D. Using a unique state-level dataset covering the period 1995–2007, this empirical study finds that once both the direct and indirect effects are taken into consideration, R & D investments significantly increase outputs. The results also show that there are substantial variations in the effects of R & D on output across the state-level average farm through technology parameters as well as through technical inefficiency. Such variations need to be taken into account when designing policies for investing public R & D in agriculture

    Justifications-on-demand as a device to promote shifts of attention associated with relational thinking in elementary arithmetic

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    Student responses to arithmetical questions that can be solved by using arithmetical structure can serve to reveal the extent and nature of relational, as opposed to computational thinking. Here, student responses to probes which require them to justify-on-demand are analysed using a conceptual framework which highlights distinctions between different forms of attention. We analyse a number of actions observed in students in terms of forms of attention and shifts between them: in the short-term (in the moment), medium-term (over several tasks), and long-term (over a year). The main factors conditioning students´ attention and its movement are identified and some didactical consequences are proposed

    3',5'-Cyclic Adenosine Monophosphate- and Ca2+-Calmodulin-Dependent Endogenous Protein Phosphorylation Activity in Membranes of the Bovine Chromaffin Secretory Vesicles: Identification of Two Phosphorylated Components as Tyrosine Hydroxylase and Protein Kinase Regulatory Subunit Type II

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    Abstract: Membranes of the secretory vesicles from bovine adrenal medulla were investigated for the presence of the endogenous protein phosphorylation activity. Seven phosphoprotein bands in the molecular weight range of 250,000 to 30,000 were observed by means of the sodium dodecyl sulphate electrophoresis and autoradiography. On the basis of the criteria of molecular weight, selective stimulation of the phosphorylation by cyclic AMP (as compared with cyclic GMP) and immunoprecipitation by specific antibodies, band 5 (molecular weight 60,300) was found to represent the phosphorylated form of the secretory vesicle-bound tyrosine hydroxylase. The electrophoretic mobility, the stimulatory and inhibitory effects of cyclic AMP in presence of Mg2+ and Zn,2+ respectively, and immunoreactivity toward antibodies showed band 6 to contain two forms of the regulatory subunits of the type II cyclic AMP-dependent protein kinase, distinguishable by their molecular weights (56,000 and 52,000, respectively). Phosphorylation of band 7 (molecular weight 29,800) was stimulated about 2 to 3 times by Ca2+ and calmodulin in the concentration range of both agents believed to occur in the secretory tissues under physiological conditions

    A single residue substitution in the receptor-binding domain of H5N1 hemagglutinin is critical for packaging into pseudotyped lentiviral particles

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    © 2012 Tang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Serological studies for influenza infection and vaccine response often involve microneutralization and hemagglutination inhibition assays to evaluate neutralizing antibodies against human and avian influenza viruses, including H5N1. We have previously characterized lentiviral particles pseudotyped with H5-HA (H5pp) and validated an H5pp-based assay as a safe alternative for high-throughput serological studies in BSL-2 facilities. Here we show that H5-HAs from different clades do not always give rise to efficient production of H5pp and the underlying mechanisms are addressed. Methodology/Findings: We have carried out mutational analysis to delineate the molecular determinants responsible for efficient packaging of HA from A/Cambodia/40808/2005 (H5Cam) and A/Anhui/1/2005 (H5Anh) into H5pp. Our results demonstrate that a single A134V mutation in the 130-loop of the receptor binding domain is sufficient to render H5Anh the ability to generate H5Anh-pp efficiently, whereas the reverse V134A mutation greatly hampers production of H5Cam-pp. Although protein expression in total cell lysates is similar for H5Anh and H5Cam, cell surface expression of H5Cam is detected at a significantly higher level than that of H5Anh. We further demonstrate by several independent lines of evidence that the behaviour of H5Anh can be explained by a stronger binding to sialic acid receptors implicating residue 134. Conclusions: We have identified a single A134V mutation as the molecular determinant in H5-HA for efficient incorporation into H5pp envelope and delineated the underlying mechanism. The reduced binding to sialic acid receptors as a result of the A134V mutation not only exerts a critical influence in pseudotyping efficiency of H5-HA, but has also an impact at the whole virus level. Because A134V substitution has been reported as a naturally occurring mutation in human host, our results may have implications for the understanding of human host adaptation of avian influenza H5N1 virusesThis work was supported by grants from the Research Fund for the Control of Infectious Diseases of Hong Kong (RFCID#08070972), the Area of Excellence Scheme of the University Grants Committee (grant AoE/M-12/-06 of the Hong Kong Special Administrative Region, China), the French Ministry of Health, and the RESPARI project of the Institut Pasteur International Network
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